Group communication sessions in a wireless communication system

ABSTRACT

In an embodiment, a server obtains a user-specified mixing preference (USMP) for an access terminal (AT) in a communication group that is different than a default mixing rule for the group communication session. The server grants non-exclusive floors to a subset of ATs in the communication group, receives media frames from each AT in the subset and generates an output frame by selectively mixing the received media frames based on the USMP, after which the output frame is sent to the AT. In another embodiment, the AT obtains the USMP and receives unmixed versions of the media frames and then selectively mixes the received media frames at the AT based on the USMP. In another embodiment, an AT detects speech and requests the floor, and the AT buffers speech while waiting for the floor request to be granted.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation-in-Part of U.S. patent applicationSer. No. 12/832,335, filed Jul. 8, 2010, entitled “GROUP COMMUNICATIONSESSIONS IN A WIRELESS COMMUNICATIONS SYSTEM”, which is by the inventorsof the subject application, is assigned to the assignee hereof and isincorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention are directed to group communicationsessions in a wireless communications session.

2. Description of the Related Art

Wireless communication systems have developed through variousgenerations, including a first-generation analog wireless phone service(1G), a second-generation (2G) digital wireless phone service (includinginterim 2.5G and 2.75G networks) and a third-generation (3G) high speeddata/Internet-capable wireless service. There are presently manydifferent types of wireless communication systems in use, includingCellular and Personal Communications Service (PCS) systems. Examples ofknown cellular systems include the cellular Analog Advanced Mobile PhoneSystem (AMPS), and digital cellular systems based on Code DivisionMultiple Access (CDMA), Frequency Division Multiple Access (FDMA), TimeDivision Multiple Access (TDMA), the Global System for Mobile access(GSM) variation of TDMA, and newer hybrid digital communication systemsusing both TDMA and CDMA technologies.

The method for providing CDMA mobile communications was standardized inthe United States by the Telecommunications IndustryAssociation/Electronic Industries Association in TIA/EIA/IS-95-Aentitled “Mobile Station-Base Station Compatibility Standard forDual-Mode Wideband Spread Spectrum Cellular System,” referred to hereinas IS-95. Combined AMPS & CDMA systems are described in TIA/EIA StandardIS-98. Other communications systems are described in the IMT-2000/UM, orInternational Mobile Telecommunications System 2000/Universal MobileTelecommunications System, standards covering what are referred to aswideband CDMA (WCDMA), CDMA2000 (such as CDMA2000 1xEV-DO standards, forexample) or TD-SCDMA.

In wireless communication systems, mobile stations, handsets, or accessterminals (AT) receive signals from fixed position base stations (alsoreferred to as cell sites or cells) that support communication links orservice within particular geographic regions adjacent to or surroundingthe base stations. Base stations provide entry points to an accessnetwork (AN)/radio access network (RAN), which is generally a packetdata network using standard Internet Engineering Task Force (IETF) basedprotocols that support methods for differentiating traffic based onQuality of Service (QoS) requirements. Therefore, the base stationsgenerally interact with ATs through an over the air interface and withthe AN through Internet Protocol (IP) network data packets.

In wireless telecommunication systems, Push-to-talk (PTT) capabilitiesare becoming popular with service sectors and consumers. PTT can supporta “dispatch” voice service that operates over standard commercialwireless infrastructures, such as CDMA, FDMA, TDMA, GSM, etc. In adispatch model, communication between endpoints (ATs) occurs withinvirtual groups, wherein the voice of one “talker” is transmitted to oneor more “listeners.” A single instance of this type of communication iscommonly referred to as a dispatch call, or simply a PTT call. A PTTcall is an instantiation of a group, which defines the characteristicsof a call. A group in essence is defined by a member list and associatedinformation, such as group name or group identification.

Conventionally, data packets within a wireless communications networkhave been configured to be sent to a single destination or accessterminal A transmission of data to a single destination is referred toas “unicast”. As mobile communications have increased, the ability totransmit given data concurrently to multiple access terminals has becomemore important. Accordingly, protocols have been adopted to supportconcurrent data transmissions of the same packet or message to multipledestinations or target access terminals. A “broadcast” refers to atransmission of data packets to all destinations or access terminals(e.g., within a given cell, served by a given service provider, etc.),while a “multicast” refers to a transmission of data packets to a givengroup of destinations or access terminals. In an example, the givengroup of destinations or “multicast group” may include more than one andless than all of possible destinations or access terminals (e.g., withina given group, served by a given service provider, etc.). However, it isat least possible in certain situations that the multicast groupcomprises only one access terminal, similar to a unicast, oralternatively that the multicast group comprises all access terminals(e.g., within a cell or sector), similar to a broadcast.

Broadcasts and/or multicasts may be performed within wirelesscommunication systems in a number of ways, such as performing aplurality of sequential unicast operations to accommodate the multicastgroup, allocating a unique broadcast/multicast channel (BCH) forhandling multiple data transmissions at the same time and the like. Aconventional system using a broadcast channel for push-to-talkcommunications is described in United States Patent ApplicationPublication No. 2007/0049314 dated Mar. 1, 2007 and entitled“Push-To-Talk Group Call System Using CDMA 1x-EVDO Cellular Network”,the contents of which are incorporated herein by reference in itsentirety. As described in Publication No. 2007/0049314, a broadcastchannel can be used for push-to-talk calls using conventional signalingtechniques. Although the use of a broadcast channel may improvebandwidth requirements over conventional unicast techniques, theconventional signaling of the broadcast channel can still result inadditional overhead and/or delay and may degrade system performance.

The 3rd Generation Partnership Project 2 (“3GPP2”) defines abroadcast-multicast service (BCMCS) specification for supportingmulticast communications in CDMA2000 networks. Accordingly, a version of3GPP2's BCMCS specification, entitled “CDMA2000 High RateBroadcast-Multicast Packet Data Air Interface Specification”, dated Feb.14, 2006, Version 1.0 C.S0054-A, is hereby incorporated by reference inits entirety.

SUMMARY

In an embodiment, a server obtains a user-specified mixing preference(USMP) for an access terminal (AT) in a communication group that isdifferent than a default mixing rule for the group communicationsession. The server grants non-exclusive floors to a subset of ATs inthe communication group, receives media frames from each AT in thesubset and generates an output frame by selectively mixing the receivedmedia frames based on the USMP, after which the output frame is sent tothe AT. In another embodiment, the AT obtains the USMP and receivesunmixed versions of the media frames and then selectively mixes thereceived media frames at the AT based on the USMP. In anotherembodiment, an AT detects speech and requests the floor, and the ATbuffers speech while waiting for the floor request to be granted.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of embodiments of the invention and many ofthe attendant advantages thereof will be readily obtained as the samebecomes better understood by reference to the following detaileddescription when considered in connection with the accompanying drawingswhich are presented solely for illustration and not limitation of theinvention, and in which:

FIG. 1 is a diagram of a wireless network architecture that supportsaccess terminals and access networks in accordance with at least oneembodiment of the invention.

FIG. 2 illustrates the carrier network according to an exampleembodiment of the present invention.

FIG. 3 is an illustration of an access terminal in accordance with atleast one embodiment of the invention.

FIG. 4A illustrates a conventional half-duplex group communicationsession process.

FIG. 4B illustrates a conventional full-duplex group communicationsession process.

FIG. 5A illustrates a group communication procedure in accordance withan embodiment of the invention.

FIG. 5B illustrates a continuation of the process of FIG. 5B inaccordance with an embodiment of the invention.

FIG. 5C illustrates a continuation of the process of FIG. 5B inaccordance with an embodiment of the invention.

FIG. 5D illustrates a continuation of the process of FIG. 5C inaccordance with an embodiment of the invention.

FIG. 6A illustrates an example of floor revocation in accordance with anembodiment of the invention.

FIG. 6B illustrates another example of floor revocation in accordancewith an embodiment of the invention.

FIG. 6C illustrates another example of floor revocation in accordancewith another embodiment of the invention.

FIG. 7 illustrates a server-based process of selectively mixing mediaframes into output frames in accordance with another embodiment of theinvention.

FIG. 8A illustrates a portion of the server-based process related to howuser-specified mixing preferences are obtained in accordance with anembodiment of the invention.

FIG. 8B illustrates a portion of the server-based process related to howuser-specified mixing preferences are obtained in accordance with anembodiment of the invention.

FIG. 9 illustrates a group communication session that incorporates someof the aspects described above with respect to FIGS. 7-8B in accordancewith an embodiment of the invention.

FIG. 10 illustrates a client-based process of selectively mixing mediaframes into output frames in accordance with another embodiment of theinvention.

FIG. 11 illustrates a group communication session that incorporates someof the aspects described above with respect to FIG. 10 in accordancewith an embodiment of the invention.

FIG. 12 illustrates a communication device that includes logicconfigured to perform functionality in accordance with an embodiment ofthe invention.

FIG. 13 illustrates a server in accordance with an embodiment of theinvention.

DETAILED DESCRIPTION

Aspects of the invention are disclosed in the following description andrelated drawings directed to specific embodiments of the invention.Alternate embodiments may be devised without departing from the scope ofthe invention. Additionally, well-known elements of the invention willnot be described in detail or will be omitted so as not to obscure therelevant details of the invention.

The words “exemplary” and/or “example” are used herein to mean “servingas an example, instance, or illustration.” Any embodiment describedherein as “exemplary” and/or “example” is not necessarily to beconstrued as preferred or advantageous over other embodiments. Likewise,the term “embodiments of the invention” does not require that allembodiments of the invention include the discussed feature, advantage ormode of operation.

Further, many embodiments are described in terms of sequences of actionsto be performed by, for example, elements of a computing device. It willbe recognized that various actions described herein can be performed byspecific circuits (e.g., application specific integrated circuits(ASICs)), by program instructions being executed by one or moreprocessors, or by a combination of both. Additionally, these sequence ofactions described herein can be considered to be embodied entirelywithin any form of computer readable storage medium having storedtherein a corresponding set of computer instructions that upon executionwould cause an associated processor to perform the functionalitydescribed herein. Thus, the various aspects of the invention may beembodied in a number of different forms, all of which have beencontemplated to be within the scope of the claimed subject matter. Inaddition, for each of the embodiments described herein, thecorresponding form of any such embodiments may be described herein as,for example, “logic configured to” perform the described action.

A High Data-rate (HDR) subscriber station, referred to herein as anaccess terminal (AT), may be mobile or stationary, and may communicatewith one or more HDR base stations, referred to herein as modem pooltransceivers (MPTs) or base stations (BS). An access terminal transmitsand receives data packets through one or more modem pool transceivers toan HDR base station controller, referred to as a modem pool controller(MPC), base station controller (BSC) and/or packet control function(PCF). Modem pool transceivers and modem pool controllers are parts of anetwork called an access network. An access network transports datapackets between multiple access terminals.

The access network may be further connected to additional networksoutside the access network, such as a corporate intranet or theInternet, and may transport data packets between each access terminaland such outside networks. An access terminal that has established anactive traffic channel connection with one or more modem pooltransceivers is called an active access terminal, and is said to be in atraffic state. An access terminal that is in the process of establishingan active traffic channel connection with one or more modem pooltransceivers is said to be in a connection setup state. An accessterminal may be any data device that communicates through a wirelesschannel or through a wired channel, for example using fiber optic orcoaxial cables. An access terminal may further be any of a number oftypes of devices including but not limited to PC card, compact flash,external or internal modem, or wireless or wireline phone. Thecommunication link through which the access terminal sends signals tothe modem pool transceiver is called a reverse link or traffic channel.The communication link through which a modem pool transceiver sendssignals to an access terminal is called a forward link or trafficchannel. As used herein the term traffic channel can refer to either aforward or reverse traffic channel.

FIG. 1 illustrates a block diagram of one exemplary embodiment of awireless system 100 in accordance with at least one embodiment of theinvention. System 100 can contain access terminals, such as cellulartelephone 102, in communication across an air interface 104 with anaccess network or radio access network (RAN) 120 that can connect theaccess terminal 102 to network equipment providing data connectivitybetween a packet switched data network (e.g., an intranet, the Internet,and/or carrier network 126) and the access terminals 102, 108, 110, 112.As shown here, the access terminal can be a cellular telephone 102, apersonal digital assistant 108, a pager 110, which is shown here as atwo-way text pager, or even a separate computer platform 112 that has awireless communication portal. Embodiments of the invention can thus berealized on any form of access terminal including a wirelesscommunication portal or having wireless communication capabilities,including without limitation, wireless modems, PCMCIA cards, personalcomputers, telephones, or any combination or sub-combination thereof.Further, as used herein, the terms “access terminal”, “wireless device”,“client device”, “mobile terminal” and variations thereof may be usedinterchangeably.

Referring back to FIG. 1, the components of the wireless network 100 andinterrelation of the elements of the exemplary embodiments of theinvention are not limited to the configuration illustrated. System 100is merely exemplary and can include any system that allows remote accessterminals, such as wireless client computing devices 102, 108, 110, 112to communicate over-the-air between and among each other and/or betweenand among components connected via the air interface 104 and RAN 120,including, without limitation, carrier network 126, the Internet, and/orother remote servers.

The RAN 120 controls messages (typically sent as data packets) sent to abase station controller/packet control function (BSC/PCF) 122. TheBSC/PCF 122 is responsible for signaling, establishing, and tearing downbearer channels (i.e., data channels) between a packet data service node160 (“PDSN”) and the access terminals 102/108/110/112. If link layerencryption is enabled, the BSC/PCF 122 also encrypts the content beforeforwarding it over the air interface 104. The function of the BSC/PCF122 is well-known in the art and will not be discussed further for thesake of brevity. The carrier network 126 may communicate with theBSC/PCF 122 by a network, the Internet and/or a public switchedtelephone network (PSTN). Alternatively, the BSC/PCF 122 may connectdirectly to the Internet or external network. Typically, the network orInternet connection between the carrier network 126 and the BSC/PCF 122transfers data, and the PSTN transfers voice information. The BSC/PCF122 can be connected to multiple base stations (BS) or modem pooltransceivers (MPT) 124. In a similar manner to the carrier network, theBSC/PCF 122 is typically connected to the MPT/BS 124 by a network, theInternet and/or PSTN for data transfer and/or voice information. TheMPT/BS 124 can broadcast data messages wirelessly to the accessterminals, such as cellular telephone 102. The MPT/BS 124, BSC/PCF 122and other components may form the RAN 120, as is known in the art.However, alternate configurations may also be used and the invention isnot limited to the configuration illustrated. For example, in anotherembodiment the functionality of the BSC/PCF 122 and one or more of theMPT/BS 124 may be collapsed into a single “hybrid” module having thefunctionality of both the BSC/PCF 122 and the MPT/BS 124.

FIG. 2 illustrates the carrier network 126 according to an embodiment ofthe present invention. In the embodiment of FIG. 2, the carrier network126 includes a packet data serving node (PDSN) 160, a broadcast servingnode (BSN) 165, an application server 170 and an Internet 175. However,application server 170 and other components may be located outside thecarrier network in alternative embodiments. The application server 170includes a media content complex (MCC) module 172, the functionality ofwhich will be described below in greater detail. The PDSN 160 providesaccess to the Internet 175, intranets and/or remote servers (e.g.,application server 170) for mobile stations (e.g., access terminals,such as 102, 108, 110, 112 from FIG. 1) utilizing, for example, acdma2000 Radio Access Network (RAN) (e.g., RAN 120 of FIG. 1). Acting asan access gateway, the PDSN 160 may provide simple IP and mobile IPaccess, foreign agent support, and packet transport. The PDSN 160 canact as a client for Authentication, Authorization, and Accounting (AAA)servers and other supporting infrastructure and provides mobile stationswith a gateway to the IP network as is known in the art. As shown inFIG. 2, the PDSN 160 may communicate with the RAN 120 (e.g., the BSC/PCF122) via a conventional A10 connection. The A10 connection is well-knownin the art and will not be described further for the sake of brevity.

Referring to FIG. 2, the broadcast serving node (BSN) 165 may beconfigured to support multicast and broadcast services. The BSN 165 willbe described in greater detail below. The BSN 165 communicates with theRAN 120 (e.g., the BSC/PCF 122) via a broadcast (BC) A10 connection, andwith the application server 170 via the Internet 175. The BCA10connection is used to transfer multicast and/or broadcast messaging.Accordingly, the application server 170 sends unicast messaging to thePDSN 160 via the Internet 175, and sends multicast messaging to the BSN165 via the Internet 175.

Generally, as will be described in greater detail below, the RAN 120transmits multicast messages, received from the BSN 165 via the BCA10connection, over a broadcast channel (BCH) of the air interface 104 toone or more access terminals 200.

Referring to FIG. 3, an access terminal 200, (here a wireless device),such as a cellular telephone, has a platform 202 that can receive andexecute software applications, data and/or commands transmitted from theRAN 120 that may ultimately come from the carrier network 126, theInternet and/or other remote servers and networks. The platform 202 caninclude a transceiver 206 operably coupled to an application specificintegrated circuit (“ASIC” 208), or other processor, microprocessor,logic circuit, or other data processing device. The ASIC 208 or otherprocessor executes the application programming interface (“API”) 210layer that interfaces with any resident programs in the memory 212 ofthe wireless device. The memory 212 can be comprised of read-only orrandom-access memory (RAM and ROM), EEPROM, flash cards, or any memorycommon to computer platforms. The platform 202 also can include a localdatabase 214 that can hold applications not actively used in memory 212.The local database 214 is typically a flash memory cell, but can be anysecondary storage device as known in the art, such as magnetic media,EEPROM, optical media, tape, soft or hard disk, or the like. Theinternal platform 202 components can also be operably coupled toexternal devices such as antenna 222, display 224, push-to-talk button228 and keypad 226 among other components, as is known in the art.

Accordingly, an embodiment of the invention can include an accessterminal including the ability to perform the functions describedherein. As will be appreciated by those skilled in the art, the variouslogic elements can be embodied in discrete elements, software modulesexecuted on a processor or any combination of software and hardware toachieve the functionality disclosed herein. For example, ASIC 208,memory 212, API 210 and local database 214 may all be used cooperativelyto load, store and execute the various functions disclosed herein andthus the logic to perform these functions may be distributed overvarious elements. Alternatively, the functionality could be incorporatedinto one discrete component. Therefore, the features of the accessterminal in FIG. 3 are to be considered merely illustrative and theinvention is not limited to the illustrated features or arrangement.

The wireless communication between the access terminal 102 and the RAN120 can be based on different technologies, such as code divisionmultiple access (CDMA), WCDMA, time division multiple access (TDMA),frequency division multiple access (FDMA), Orthogonal Frequency DivisionMultiplexing (OFDM), the Global System for Mobile Communications (GSM),or other protocols that may be used in a wireless communications networkor a data communications network. The data communication is typicallybetween the client device 102, MPT/BS 124, and BSC/PCF 122. The BSC/PCF122 can be connected to multiple data networks such as the carriernetwork 126, PSTN, the Internet, a virtual private network, and thelike, thus allowing the access terminal 102 access to a broadercommunication network. As discussed in the foregoing and known in theart, voice transmission and/or data can be transmitted to the accessterminals from the RAN using a variety of networks and configurations.Accordingly, the illustrations provided herein are not intended to limitthe embodiments of the invention and are merely to aid in thedescription of aspects of embodiments of the invention.

FIG. 4A illustrates a conventional half-duplex group communicationsession (e.g., a call, a transport session, etc.) process. The groupcommunication session of FIG. 4A may correspond to a group communicationsession supported by IP multicasting protocols, or IP unicastingprotocols. In IP multicasting, a downlink broadcast channel (BCH)carries a single multicast flow within one or more sectors to reach each‘listening’ multicast group member, while a separate scheduling message(e.g., a broadcast overhead message (BOM)) is transmitted on a downlinkcontrol channel that indicates how the multicast group members can tuneto the downlink BCH. In IP unicasting, each group message is transmittedto each group communication session participant, or multicast groupmember, as a separate unicast message that is addressed to each groupmember individually.

Referring to FIG. 4A, in 400, a given AT (“AT A”) sends a request to theapplication server 170 via the RAN 120 to initiate a group communicationsession. For example, the group communication session may correspond toa push-to-talk (PTT) or push-to-transfer (PTX) session, and thetransmission of the request in 400 may be prompted based on a user of ATA pressing a PTT or PTX button on AT A. The application server 170receives the group communication session request from AT A, andtransmits an announce message in one or more sectors of the wirelesscommunication system 100, 405. At least ATs B . . . E receive theannounce message, and determine to join the announced groupcommunication session. Accordingly, ATs B . . . E send a call acceptmessage to the application server 170, and also send a registrationmessage (e.g., BCMCSFlowRegistration message) to the RAN 120 to registerto the group communication session, 410 and 415. The call accept messageand registration message from each of ATs B . . . E may either be sentwithin separate messages on a reverse link access channel, oralternatively may be bundled within the same message.

After receiving a call accept message from a first responder to theannounce message from among ATs B . . . E, the application server 170grants the floor for the group communication session to AT A, 420.Accordingly, after receiving the floor-grant message, AT A plays a toneto indicate to a user of AT A that the user can begin speaking, and AT Abegins transmitting frames on a reverse link channel to the applicationserver 170, 425. The series of frame transmissions from 425 cancorrespond to data frames that actually include voice data, oralternatively can correspond to silence frames that do not actuallyinclude voice data.

Each frame transmission can correspond to a real-time transport protocol(RTP) packet or datagram, or alternatively a RTCP (RTP Control Protocol)packet. A header portion of a 40-octet overhead RTP packet may beconfigured as follows:

TABLE 1 Example of a RTP packet header 0 1 2 3 4 5 6 7 8 9 10 11 12 1314 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Octet 1, 5, 9 . .. Octet 2, 6, 10 . . . Octet 3, 7, 11 . . . Octet 4, 8, 12 . . . 1-4Version IHL Type of service Total length 5-8 Identification FlagsFragment offset  9-12 Time to live Protocol Header checksum 13-16 Sourceaddress 17-20 Destination address 21-24 Source port Destination port25-28 Length Checksum 29-32 V = 2 P X CC M PT Sequence number 33-36Timestamp 37-40 Synchronization source (SSRC) number

Referring to Table 1, the fields of the RTP packet header portion arewell-known in the art. However, certain fields are discussed in moredetail with respect to embodiments described in more detail below, andas such will be referred to briefly in this section. For example, thecontribution count (CC) field, Sequence Number field, Timestamp fieldand SSRC number field will now be addressed briefly. The CC field is anoptional field that can hold a contributing source (CSRC) count value.Although not shown on the header diagram of Table 1 (above), the 12octet header of the CC field can optionally be expanded to include morecontributing sources. Contributing sources can be added by a mixer atthe application server 170, and are relevant for conferencingapplications where elements of the data payload have originated fromdifferent computers. For point-to-point communications, CSRCs are notnecessarily required. The Sequence Number field holds a unique referencenumber which increments by one for each RTP packet sent from aparticular source, or AT. The Sequence Number field allows the receiverto reconstruct the sender's packet sequence. The Timestamp fieldcorresponds to the time that the RTP packet was transmitted by the AT.The Timestamp field allows the receiving AT(s) to buffer and playout thedata in a continuous stream. The SSRC number field corresponds to anumber that identifies the source of the RTP packet, which in 425identifies AT A. The SSRC number can be provisioned by the applicationserver 170 at the start of the group communication session.

After the RTP header portion, the RTP packet includes a data payloadportion. The data payload portion can include digitized samples of voiceand/or video. The length of the data payload can vary for different RTPpackets. For example, in voice RTP packets, the length of the voicesample carried by the data payload may correspond to 20 milliseconds(ms) of sound. Generally, for longer media durations (e.g., higher-rateframes), the data payload either has to be longer as well, or else thequality of the media sample is reduced.

Returning to 425 of FIG. 4A, the frames transmitted from AT A cancorrespond to full-rate frames (e.g., 8.6 kpbs) that have a large datapayload in the RTP packet, half-rate frames (e.g., 4.3 kpbs) thatinclude a ‘medium’ data payload in the RTP packet, 1/8th rate frames(e.g., 1.0 kpbs) that include a small data payload in the RTP packet,and so on. While references are generally made to EVRC-A, it will bereadily apparent how these embodiments can be modified to accommodateother vocoders that include different frame rate options. As will beappreciated, when a user of AT A is speaking, AT A transmits higher-rateframes than when the user of AT A is not speaking and AT A istransmitting silence frames. The application server 170 includes a mediacontrol complex (MCC) 172 module that handles the receipt of a mediastream from floor-holders, and the transcoding of an output stream toone or more ‘listening’ group members to the group communicationsession. In other words, the MCC module 172 replicates and re-broadcaststhe frames within RTP packets from AT A to each of ATs B . . . E.Accordingly, a series of frame transmissions from AT A that are receivedat the MCC module 172 of the application server 170 may be representedas follows:

TABLE 2 Media Frames arriving at the MCC from AT A at ‘t’ interval forHalf- Duplex 10t 9t 8t 7t 6t 5t 4t 3t 2t T A ▪ ½ ▪ ½ □ ⅛ □ ⅛ ▪ ½ ▪ ½ □ ⅛▪ ½ □ ⅛ ▪ ½ B — — — — — — — — — — C — — — — — — — — — — D — — — — — — —— — — E — — — — — — — — — —wherein time intervals 10 t . . . T each include one frame (e.g., RTPpacket) having a given data-rate from AT A. It may be assumed that the▪1/2 frames correspond to data frames (e.g., including voice data),whereas the □1/8 correspond to silence frames. However, it isappreciated that it is at least possible for a ▪1/2 frame to include alimited amount of noise, similar to a silence frame. Also, because FIG.4A is a half-duplex group communication session, it is noted that Table2 (above) indicates that AT A is transmitting frames (e.g., within oneor more RTP packets), whereas ATs B . . . E are not transmitting anypackets. The frames (e.g., RTP packets) illustrated in Table 2correspond to an input stream of packets or frames that are received atthe application server 170.

As noted above, the MCC module 172 receives the input stream asillustrated above in Table 2, and generates or transcodes an outputstream that is transmitted to ATs B . . . E. Accordingly, based on Table2, the output stream generated by the MCC module 172 of the applicationserver 170 may be configured as follows:

TABLE 3 Media Frames in the output stream from the MCC to ATs B . . . Efor Half-Duplex 10t 9t 8t 7t 6t 5t 4t 3t 2t T A — — — — — — — — — — B ▪½ ▪ ½ □ ⅛ □ ⅛ ▪ ½ ▪ ½ □ ⅛ ▪ ½ □ ⅛ ▪ ½ C ▪ ½ ▪ ½ □ ⅛ □ ⅛ ▪ ½ ▪ ½ □ ⅛ ▪ ½□ ⅛ ▪ ½ D ▪ ½ ▪ ½ □ ⅛ □ ⅛ ▪ ½ ▪ ½ □ ⅛ ▪ ½ □ ⅛ ▪ ½ E ▪ ½ ▪ ½ □ ⅛ □ ⅛ ▪ ½▪ ½ □ ⅛ ▪ ½ □ ⅛ ▪ ½

As shown in Table 3 (above), the output stream is configured such thatAT A's frame transmissions are not transmitted back to AT A, but arerather transmitted to ATs B . . . E in Table 2, above.

As the output stream is generated by the MCC module 172, the applicationserver 170 transmits RTP packets including output frames from the outputstream to ATs B . . . E, 430, as a series of group messages, and ATs B .. . E monitor the group messages for the group communication session,435 and 440. The group communication session then continues for a periodof time, until a user of AT A determines to give up the floor, 445. 445can correspond to an explicit instruction from AT A to give up thefloor, or based on a period of inactivity from AT A.

After determining AT A has given up the floor to the group communicationsession, the application server 170 sends a floor-release message to ATsB . . . E, 450. Assume that a user of AT B and at least one of ATs C . .. E determine to attempt to gain control of the floor, and send floorrequest messages to the application server 170, 455 and 460. Theapplication server 170 thereby receives multiple floor request messages,and evaluates priority levels of the ATs requesting the floor todetermine the AT that will next be granted the floor. For example, basedon the type of group communication session, the application server 170may evaluate one or more priority tables maintained at the RAN 120, andmay grant the floor to a highest-priority AT from among the ATsrequesting the floor. For example, the priority tables may be configuredas follows:

TABLE 4 Priority Tables to Evaluate Floor Requests Direct Adhoc ClosedClosed Chat Calls Calls Group Calls room Calls User Priority UserPriority User Priority User Priority A 7 A 7 A 2 A 2 B 7 B 7 B 5 B 5 C 7C 7 C 7 C 7 D 7 D 7 D 1 D 1 E 7 E 7 E 3 E 3

In 465, assume that the application server 170 determines AT B has thehighest priority level from among the requesting AT for the call-type ofthe group communication session, and the application server 170 sends afloor-grant message to AT B. Next, AT B plays a tone to notify a user ofAT B that AT B now has the floor, and AT B begins transmitting frames(e.g., data frames, silence frames, etc.) within one or more RTP packetsto the application server 170, 470, which are then converted into anoutput stream by the MCC module 172 and re-transmitted to ATs A and C .. . E, 475. It will be appreciated that 470 and 475 are performed in thesame manner as 425 and 430 as described above with respect to AT A, andas such 470 and 475 will not be described further for the sake ofbrevity.

As is characteristic of a half-duplex session, certain ATs in the groupcommunication session of FIG. 4A only transmit frames (e.g., within RTPpackets), while other ATs in the group communication session onlyreceive frames (e.g., within RTP packets). An alternative to the processof FIG. 4A is a full-duplex group communication session, which isdescribed below with respect to FIG. 4B. In a full-duplex session, eachparticipant to the session can both transmit and receive frames (e.g.,within RTP packets).

FIG. 4B illustrates a conventional full-duplex group communicationsession (e.g., a call, a data transport session, etc.) process. As inFIG. 4A, the group communication session of FIG. 4B may correspond to agroup communication session supported by IP multicasting protocols, orIP unicasting protocols. Referring to FIG. 4B, 400B through 415Bcorrespond to 400 through 415 of FIG. 4A, and as such will not bediscussed further for the sake of brevity.

In 420B, instead of granting the floor to the session initiator (i.e.,AT A), the application server 170 sends a message to each AT that hasjoined the group communication session indicating that the session canbegin, 420B. Upon receiving the message 420B, any of ATs A . . . E canbegin speaking and thereby send data frames, or else can remain silentand send silence frames, 425B, 430B, 435B.

An example of the input stream from ATs A . . . E (e.g., the framesincluded within RTP packets from ATs A . . . E for particular timeslots)that are received at the MCC module 172 of the application server 170may be represented as follows:

TABLE 5 Media Frames arriving at the MCC from ATs A . . . E at ‘t’interval for Full-Duplex 10t 9t 8t 7t 6t 5t 4t 3t 2t T A ▪ ½ ▪ ½ ▪ ½ ▪ ½▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ B □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ C □ ⅛□ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ D □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛□ ⅛ □ ⅛ E □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛

Referring to Table 5 (above), each of ATs A . . . E is transmittingframes over timeslots 10 t . . . T at a given data rate. In particular,AT A is sending a series of half-rate frames (e.g., which indicates thata user of AT A is likely speaking to ATs B . . . E, and sending voicedata), while ATs B . . . E are sending a series of 1/8th rate frames(e.g., which indicates that the users of ATs B . . . E are likelylistening to AT A, have walked away from their phones, etc.).

Returning to FIG. 4B, 450B, the MCC module 172 of the application server170 includes each of the frames from the input streams at each timeinterval t, de jitters the aggregated media stream, and then generatesan output stream that includes all the media content from each of ATs A. . . E for that time interval. The application server 170 then sendsthe resultant media stream to each of ATs A . . . E as a series ofaggregated frames within one or more RTP packets, which ATs A . . . Ereceive the resultant media stream based on monitoring, 445B, 455B and460B. However, it is appreciated that each of ATs A . . . E receives anaggregated media stream containing frames from all session participants,except itself, to avoid feedback problems. Thus, AT A receives an outputstream composed of aggregated media from ATs B . . . E, AT B receives anoutput stream composed of aggregated media from ATs A and C . . . E, andso on.

As noted above, the MCC module 172 receives the frames from ATs A . . .E (i.e., the input stream) as illustrated above in Table 5 (above), andthen generates or transcodes output streams that are transmitted to ATsA . . . E at 450B (e.g., which are each different because each outputstream omits the frames of the input stream received from the target inorder to reduce feedback). Accordingly, based on Table 5 (above), theoutput stream generated by the MCC module 172 of the application server170 over timeslots 10 t . . . T may be configured as follows:

TABLE 6 Media Frames in the output streams from the MCC to ATs A . . . Efor Full-Duplex 10t 9t 8t 7t 6t 5t 4t 3t 2t T A □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛□ ⅛ □ ⅛ □ ⅛ □ ⅛ (B) (B) (B) (B) (B) (B) (B) (B) (B) (B) □ ⅛ □ ⅛ □ ⅛ □ ⅛□ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ (C) (C) (C) (C) (C) (C) (C) (C) (C) (C) □ ⅛ □ ⅛□ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ (D) (D) (D) (D) (D) (D) (D) (D) (D) (D)□ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ (E) (E) (E) (E) (E) (E) (E) (E)(E) (E) B ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ (A) (A) (A) (A) (A)(A) (A) (A) (A) (A) □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ (C) (C) (C)(C) (C) (C) (C) (C) (C) (C) □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ (D)(D) (D) (D) (D) (D) (D) (D) (D) (D) □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛□ ⅛ (E) (E) (E) (E) (E) (E) (E) (E) (E) (E) C ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪½ ▪ ½ ▪ ½ ▪ ½ (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) □ ⅛ □ ⅛ □ ⅛ □ ⅛□ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ (B) (B) (B) (B) (B) (B) (B) (B) (B) (B) □ ⅛ □ ⅛□ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ (D) (D) (D) (D) (D) (D) (D) (D) (D) (D)□ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ (E) (E) (E) (E) (E) (E) (E) (E)(E) (E) D ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ (A) (A) (A) (A) (A)(A) (A) (A) (A) (A) □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ (B) (B) (B)(B) (B) (B) (B) (B) (B) (B) □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ (C)(C) (C) (C) (C) (C) (C) (C) (C) (C) □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛□ ⅛ (E) (E) (E) (E) (E) (E) (E) (E) (E) (E) E ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪ ½ ▪½ ▪ ½ ▪ ½ ▪ ½ (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) □ ⅛ □ ⅛ □ ⅛ □ ⅛□ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ (B) (B) (B) (B) (B) (B) (B) (B) (B) (B) □ ⅛ □ ⅛□ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ (C) (C) (C) (C) (C) (C) (C) (C) (C) (C)□ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ □ ⅛ (D) (D) (D) (D) (D) (D) (D) (D)(D) (D)

As shown in Table 6 (above), due to a simplistic brute force forwardingimplementation of the group communication session, the aggregated mediaframes to ATs A . . . E at each timeslot of the output stream has atotal data-rate equal to the sum of the data-rates for frames (e.g., orRTP packets) from ATs other than itself.

With respect to the conventional half-duplex implementation for thegroup communication session in FIG. 4A, it will be appreciated thatbandwidth utilization is superior as compared to the full-dupleximplementation for the group communication session of FIG. 4A. However,the inability of ATs to transmit to the group can, at times, beproblematic (e.g., if a current floor-holder does not give up the floorand keeps on talking about irrelevant issues). In half-duplex, thecurrent floor-holder would be oblivious to the sentiment of the groupbecause the floor-holder cannot receive feedback from the othergroup-members until the floor is released.

This problem does not occur in the full-duplex implementation of FIG.4B. However, the bandwidth requirements of a full-duplex implementationare high, because for N group communication session participants, eachparticipant receives an aggregated output stream having N−1 combinedmedia flows, which consumes a relatively high amount of bandwidth. Also,aggregating a high number of media frames to form the media frames ofthe output stream can be processing intensive at the application server170. Also, the MCC module 172 of the application server 170 does notdistinguish between media flows. Thus, silence frames are granted thesame priority as data frames in the output stream when the framescontend for the same timeslot in the output stream.

Accordingly, embodiments which will now be described in more detail aredirected to a hybrid implementation that includes certain properties ofboth half-duplex and full-duplex implementations. As will be describedbelow in more detail, each of a plurality of participants to a groupcommunication session can be temporarily granted the ‘floor’, orpermission to speak to the group, based on a recognition of whichparticipants have currently expressed an intention to speak to thegroup. As used herein, granting the ‘floor’ to a particular AT meansthat the particular AT has a non-exclusive permission to speak to thegroup, whereby one or more other ATs can also potentially havepermission to speak to the group. Accordingly, references tofloor-grants below will be understood to correspond to non-exclusivefloor-grants or granting a non-exclusive floor. By contrast,conventional half-duplex sessions typically permit only one floorholderat a time, so the floor in conventional half-duplex sessions can be saidto correspond to an exclusive floor.

FIG. 5A illustrates a group communication procedure in accordance withan embodiment of the invention. Referring to FIG. 5A, in 500A, a givenAT (“AT A”) requests initiation of a group communication session withATs B . . . X to be arbitrated by the application server 170. In anexample, the group communication session can correspond to avoice-over-IP (VoIP) session, a Push-to-Talk (PTT) session or aPush-to-Transfer (PTX) session. The application server 170 receives thesession initiation request and announces the group communication sessionto ATs B . . . X, 505A. Next, assume that each of ATs B . . . X receivethe announce message for the group communication session in theirrespective sector, and further that each of ATs B . . . X decide toaccept the announced session and thereby register to the groupcommunication session within their respective sector and provide anindication of call-acceptance to the application server 170, 510A, 515A,520A and 525A.

After at least one of the call acceptance messages is received from ATsB . . . X at the application server 170, the application server 170 setsup the group communication session by sending status and contactmessages to each AT that has accepted the group communication session,530A and 535A. For example, the status message contains informationregarding which group session participants have joined the groupcommunication session. In another example, the contact message containsinformation regarding how ATs A . . . X can contact the MCC that ishandling the exchange of media between the respective ATs during thegroup communication session.

At this point, assume that AT A detects that its user has performed agiven type of user behavior that is indicative of a desire to speak tothe group during the group communication session, 540A. In an example,the detection of 540A can correspond to a detection that the user of ATA has started to speak. In another example, the detection of 540A can bemore explicit, such as a user of AT A pressing a CALL or PTT button onAT A that is interpreted as a request to speak to the group.

In response to the detection of 540A, AT A transmits a floor-request tothe RAN 120, which is forwarded to the application server 170, 545A.Also, while AT A waits to receive the floor for the group communicationsession, AT A buffers media (e.g., speech) from the user of AT A, 550A.The application server 170 receives the floor-request from AT A andsends a floor-grant message to AT A, 555A. Upon receiving thefloor-grant message, AT A begins sending media (e.g., audio), includingthe media buffered in 550A, to the application server 170 fortransmission to the remaining group session participants (i.e., ATs B .. . X), 560A. Hereinafter, the stream of media frames from AT A that aresent from AT A to the application server 170 for re-transmission to ATsB . . . X will be referred to as input stream A.

While not shown explicitly in FIG. 5A, blocks 540A through 550A can beomitted in at least one alternative embodiment of the invention. In thiscase, AT A's request to initiate or originate the group communicationsession functions as an implicit indication to the application server170 that the user of AT A wants to speak to the group. Thus, in thisalternative embodiment, the application server 170 can send thefloor-grant message of 555A to AT A after sending the status and contactmessages in 530A and 535A. As will be appreciated, in a scenario wherethe originator is automatically allocated the floor during sessionset-up, this floor could still be revoked if certain conditions aresatisfied, as described below with respect to FIGS. 6A-6C.

The application server 170 receives input stream A from AT A andforwards media contained in input stream A from AT A to ATs B . . . Xwithin an output stream, 565A. As will be appreciated, no other groupsession participants are sending media to the group at this point, suchthat the output stream contains media only from AT A in 565A. Also, theapplication server 170 need not send the media contained in input streamA back to AT A, such that no output stream is sent back to AT A in 565A.In 570A, the application server 170 sends a group in-call status updatemessage to each group session participant to notify the respectiveparticipants with regard to which ATs are currently speaking to thegroup. In this case, the group in-call status message of 570A informsATs A . . . X that AT A is currently transmitting media to the group.

FIG. 5B illustrates a continuation of the process of FIG. 5A inaccordance with an embodiment of the invention. Referring to FIG. 5B,after 570A of FIG. 5A, at some point during the group communicationsession while AT A is sending media to the group, assume that AT Bdetects that its user has performed a given type of user behavior thatis indicative of a desire to speak to the group during the groupcommunication session, 500B. Similar to 540A of FIG. 5A, the detectionof 500B can correspond to a detection that the user of AT B has startedto speak and/or that the user of AT B has pressed a CALL or PTT buttonon AT B that is interpreted as a request to speak to the group.

In response to the detection of 500B, AT B transmits a floor-request tothe RAN 120, which is forwarded to the application server 170, 505B.Also, while AT B waits to receive a non-exclusive floor for the groupcommunication session, AT B buffers media (e.g., speech) from the userof AT B, 510B. The application server 170 receives the floor-requestfrom AT B and determines whether to grant the non-exclusive floor to ATB, 515B. In an example, the determination of 515B can be based onwhether a threshold number of ATs have already been granted anon-exclusive floor for the group communication session. In thisembodiment, if the threshold number of ATs have already been granted thenon-exclusive floor, then AT B's request will be denied. Alternatively,if the threshold number of ATs have already been granted thenon-exclusive floor and AT B has a high-priority, then anotherlower-priority AT that has the floor can have its floor revoked, afterwhich the revoked floor can be transferred to AT B. In the embodiment ofFIG. 5B, it may be assumed that the threshold number of ATs that canconcurrently hold the floor, and thereby speak to the group at the sametime, is at least equal to two (2). Accordingly, the application server170 determines to grant AT B the floor by which AT B can speak to thegroup in 515B.

Thus, the application server 170 sends a floor-grant message to AT B,520B. During this process of setting-up the floor at AT B, AT A alsoholds the floor to the hybrid group communication session and continuesto send media to the application server 170, as input stream A, fortransmission to the group, 525B. Upon receiving the floor-grant message,AT B begins sending media (e.g., audio), including the media buffered in510B, to the application server 170 for transmission to the remaininggroup session participants (i.e., ATs A and C . . . X), 530B.Hereinafter, the stream of media frames from AT B that are sent from ATB to the application server 170 for re-transmission to ATs A and C . . .X will be referred to as input stream B.

The application server 170 receives input streams A and B from ATs A andB, respectively, and selectively mixes the individual frames from therespective input streams to form the output stream that will betransmitted to the group, 535B. The selective mixing that occurs at 535Bis based upon a default mixing rule that is executed by the applicationserver 170 by default for the session, i.e., without expressinstructions to mix differently. Below, the default mixing rule is (i)if there is only one non-exclusive floorholder AT to provide a mediaframe for a particular timeslot, each AT in the group except for thenon-exclusive floorholder AT is delivered an unmixed output frame thatincludes the media frame from the non-exclusive floorholder AT, and (ii)if there are multiple non-exclusive floorholder ATs providing mediaframes for the particular timeslot, each AT in the group is delivered amixed or unmixed output frame that includes media frame(s) provided fromeach non-exclusive floorholder AT, except that the non-exclusivefloorholder ATs will not have their own media frame mixed into theirparticular output frames. However, in other embodiments, differentdefault mixing rules can be implemented.

For example, in accordance with the above-noted default mixing rule, theoutput stream that is generated for transmission to ATs C . . . Xcorresponds to a series of mixed media frames (or output frames) thateach include a mixed combination of the media from input streams A andB. However, because transmitting ATs do not receive their own media inthe output stream that is fed back to the transmitting ATs from theapplication server 170, it will be appreciated that the output streamthat is generated for transmission to AT A corresponds to input stream Band that the output stream that is generated for transmission to AT Bcorresponds to input stream A. Accordingly, in 540B, the applicationserver 170 forwards the output streams to ATs A . . . X such that AT Areceives an output stream containing media from input stream B (e.g.,output stream B), AT B receives an output stream containing media frominput stream A (e.g., output stream A) and ATs C . . . X each receive anoutput stream containing media from input streams A and B (e.g., outputstream A+B). Examples of mixing media frames of different group sessionparticipants are provided in more detail within co-pending U.S.Provisional Application No. 61/224,797, entitled “MEDIA FORWARDING FOR AGROUP COMMUNICATION SESSION IN A WIRELESS COMMUNICATIONS SYSTEM”, filedon Jul. 10, 2009, by Ashu Razdan, Arul Ananthanarayanan and DevangBhatt, assigned to the assignee of the subject application, having andhereby incorporated by reference in its entirety.

In 545B, the application server 170 sends a group in-call status updatemessage to each group session participant to notify the respectiveparticipants with regard to which ATs are currently speaking to thegroup. In this case, the group in-call status message of 545B informsATs A . . . X that ATs A and B are currently transmitting media to thegroup.

FIG. 5C illustrates a continuation of the process of FIG. 5B inaccordance with an embodiment of the invention. Also, while yet to beaddressed, FIG. 5C could also constitute a continuation of the processof any of FIGS. 6A through 6C, in the sense that FIG. 5C represents anexample whereby a group communication session is already establishedbetween ATs A . . . X with ATs A and B currently holding the floor andspeaking to the group.

Referring to FIG. 5C, after 545B of FIG. 5B (or after any of FIG. 6A, 6Bor 6C), at some point during the group communication session while ATs Aand B are each sending media to the group, assume that AT C detects thatits user has performed a given type of user behavior that is indicativeof a desire to speak to the group during the group communicationsession, 500C. Similar to 540A of FIGS. 5A and 500B of FIG. 5B, thedetection of 500C can correspond to a detection that the user of AT Chas started to speak and/or that the user of AT C has explicitlyrequested to speak to the group (e.g., by pressing a CALL or PTT buttonon AT C).

In response to the detection of 500C, AT C transmits a floor-request tothe RAN 120, which is forwarded to the application server 170, 505C.Also, while AT C waits to receive the floor for the group communicationsession, AT C buffers media (e.g., speech) from the user of AT C, 510C.The application server 170 receives the floor-request from AT C anddetermines whether to grant a non-exclusive floor to AT C, 515C. In anexample, as discussed above with respect to 515B of FIG. 5B, thedetermination of 515C can be based on whether a threshold number of ATshave already been granted the floor for the group communication session.In this embodiment, if the threshold number of ATs have already beengranted non-exclusive floors, then AT C's request will be denied.Alternatively, if the threshold number of ATs have already been grantedthe floor and AT C has a high-priority, then another lower-priority ATthat has the floor can have its floor revoked, after which the revokedfloor can be transferred to AT C. In the embodiment of FIG. 5C, it maybe assumed that the threshold number of ATs that can concurrently holdthe floor, and thereby speak to the group at the same time, is at leastequal to three (3). Accordingly, the application server 170 determinesto grant AT C the floor by which AT C can speak to the group in 515C.

Thus, the application server 170 sends a floor-grant message to AT C,520C. During this process of setting-up the floor at AT C, ATs A and Balso hold the floor to the hybrid group communication session andcontinue to send media to the application server 170, as input streams Aand B, respectively, for transmission to the group, 525C and 530C. Uponreceiving the floor-grant message, AT C begins sending media (e.g.,audio), including the media buffered in 510C, to the application server170 for transmission to the remaining group session participants (i.e.,ATs A, B and D . . . X), 535C. Hereinafter, the stream of media framesfrom AT C that are sent from AT C to the application server 170 forre-transmission to ATs A, B and D . . . X will be referred to as inputstream C.

The application server 170 receives input streams A, B and C from ATs A,B and C, respectively, and selectively mixes the individual frames fromthe respective input streams to form the output stream that will betransmitted to the group, 540C (e.g., in accordance with the defaultmixing rule). Specifically, the output stream that is generated fortransmission to ATs D . . . X corresponds to a series of mixed mediaframes that each include a mixed combination of the media from inputstreams A, B and C. However, because transmitting ATs do not receivemedia in the output stream from the application server 170 that wasprovided from their own respective input stream, it will be appreciatedthat the output stream that is generated for transmission to AT Acorresponds to a mixed combination of the media from input streams B andC, that the output stream that is generated for transmission to AT Bcorresponds to a mixed combination of the media from input streams A andC, and that the output stream that is generated for transmission to AT Ccorresponds to a mixed combination of the media from input streams A andB.

Accordingly, in 545C, the application server 170 forwards the outputstreams to ATs A . . . X such that AT A receives an output streamcontaining media from input streams B and C (e.g., output stream B+C),AT B receives an output stream containing media from input streams A andC (e.g., output stream A+C), AT C receives an output stream containingmedia from input streams A and B (e.g., output stream A+B), and ATs D .. . X each receive an output stream containing media from input streamsA, B and C (e.g., output stream A+B+C). In 550C, the application server170 sends a group in-call status update message to each group sessionparticipant to notify the respective participants with regard to whichATs are currently speaking to the group. In this case, the group in-callstatus message of 550C informs ATs A . . . X that ATs A, B and C arecurrently transmitting media to the group.

FIG. 5D illustrates a continuation of the process of FIG. 5C inaccordance with an embodiment of the invention, such that FIG. 5Drepresents an example whereby a group communication session is alreadyestablished between ATs A . . . X with ATs A, B and C currently holdingthe floor and speaking to the group.

Referring to FIG. 5D, after 550C of FIG. 5C, at some point during thegroup communication session while ATs A, B and C are each sending mediato the group, assume that AT D detects that its user has performed agiven type of user behavior that is indicative of a desire to speak tothe group during the group communication session, 500D. Similar to 540Aof FIG. 5A, 500B of FIG. 5B and/or 500C of FIG. 5C, the detection of500D can correspond to a detection that the user of AT D has started tospeak and/or that the user of AT D has explicitly requested to speak tothe group (e.g., by pressing a CALL or PTT button on AT D).

In response to the detection of 500D, AT D transmits a floor-request tothe RAN 120, which is forwarded to the application server 170, 505D.Also, while AT D waits to receive the floor for the group communicationsession, AT D buffers media (e.g., speech) from the user of AT C, 510D.The application server 170 receives the floor-request from AT D anddetermines whether to grant the floor to AT D, 515D. In an example, asdiscussed above with respect to 515B of FIG. 5B and/or 515C of FIG. 5C,the determination of 515D can be based on whether a threshold number ofATs have already been granted non-exclusive floors for the groupcommunication session. In this embodiment, if the threshold number ofATs have already been granted non-exclusive floors, then AT D's requestwill be denied. Alternatively, if the threshold number of ATs havealready been granted the floor and AT D has a high-priority, thenanother lower-priority AT that has the floor can have its floor revoked,after which the floor can be transferred to AT D.

In the embodiment of FIG. 5D, it may be assumed that the applicationserver 170 determines to reject the floor-request from AT D in 515D(e.g., because the threshold number of floor-holders for the groupcommunication session has been reached or for some other reason). Thus,the application server 170 sends a floor-reject message to AT D, 520D.AT D receives the floor-reject message and stops buffering media, 525D(e.g., because AT D was rejected permission to send the media to thegroup at this time). AT D can also optionally notify its user withregard to the floor-rejection (e.g., so that the user of AT D can stopspeaking under the assumption that his/her media will be sent out to thegroup), for example, by outputting an audio or visual alert, 530D.

During this process of attempting to set-up but ultimately rejecting thefloor for AT D, ATs A, B and C still hold the floor to the hybrid groupcommunication session and continue to send media to the applicationserver 170, as input streams A, B and C, respectively, for transmissionto the group, 535D, 540D and 545D. The remaining of FIG. 5Dsubstantially corresponds to portions of FIG. 5C, and as such will notbe described further for the sake of brevity. In particular, 550Dthrough 560D of FIG. 5D substantially correspond to 540C through 550C,respectively, of FIG. 5C.

As will be appreciated by one of ordinary skill in the art, the processof FIG. 5D is an example whereby a group session participant is notpermitted to speak to the group during the group communication session,and is restricted to receiving the media from the participants that havereceived permission to speak to the group (i.e., the floor). Inembodiments that will be described below with respect to FIGS. 6Athrough 6C, an AT that was previously granted the floor can have itsfloor revoked. The floor-revocation can be initiated by the AT itself(e.g., as in FIG. 6A), by a high-priority AT or ‘superuser’ (e.g., as inFIG. 6B) or upon the initiative of the application server 170 (e.g., asin FIG. 6C).

Accordingly, FIG. 6A illustrates an example of floor revocation inaccordance with an embodiment of the invention. In particular, FIG. 6Aillustrates an example whereby ATs A . . . X are already engaged in agroup communication session with ATs A, B and C each holding anon-exclusive floor and speaking to the group. Thus, FIG. 6A can beconsidered to be a continuation of the process of FIG. 5C, because FIG.5C establishes a group communication session with similar conditions.

Referring to FIG. 6A, after 550C of FIG. 5C, at some point during thegroup communication session while ATs A, B and C are each sending mediato the group, assume that AT C detects that its user has performed agiven type of user behavior that is indicative of the user no longerhaving a desire to speak to the group during the group communicationsession, 600A. In an example, the detection of 600A can correspond to acessation of the user behavior that caused the detection of 500C of FIG.5C. For example, if AT C detected that its user had the intention tospeak to the group based on the user beginning to speak into AT C at500C, then the detection that the user no longer has the intention tospeak to the group in 600A can correspond to when the user stopsspeaking. Alternatively, the detection of 600A can correspond to aseparate or supplemental action by the user that functions to explicitlyindicate the user's intention to stop speaking to the group. Forexample, if AT C detected that its user had the intention to speak tothe group based on the user pressing CALL or PTT button on AT C, thenthe detection that the user no longer has the intention to speak to thegroup in 600A can correspond to when the user presses another button onAT C (e.g., a second press of the CALL or PTT button, a press of an ENDor cancel button, a detection of voice-inactivity for a threshold periodof time, etc.). As will be appreciated, any of the above-noted ‘buttons’can correspond to ‘physical’ tactile-response type-buttons, or to ‘soft’buttons (e.g., touch-screen type buttons, menu selections, etc.).

In response to the detection of 600A, AT C transmits a request to revoke(drop or release) its non-exclusive floor to the RAN 120, which isforwarded to the application server 170, 605A. While not shown withinFIG. 6A, AT C can optionally cease transmission of media to theapplication server 170 for transmission to the group even before theapplication server 170 acknowledges that AT C's floor has been revoked(i.e., dropped or released). The application server 170 receives therequest to revoke the non-exclusive floor from AT C, drops AT C'snon-exclusive floor and then acknowledges that AT C's floor has beenrevoked, 610A. At this point, the application server 170 stops mixingmedia from input stream C into any of the output streams to ATs A . . .X, 615A. While not shown in FIG. 6A, AT C can also optionally notify itsuser with regard to the floor-revocation (e.g., so that the user of AT Cis aware that his/her speech is no longer being sent to the group).

After revoking AT C's non-exclusive floor to the group communicationsession, it will be appreciated that ATs A and B still holdnon-exclusive floors to the hybrid group communication session andcontinue to send media to the application server 170, as input streams Aand B, respectively, for transmission to the group, 620A and 625A. Theremaining of FIG. 6A substantially corresponds to portions of FIG. 5B,and as such will not be described further for the sake of brevity. Inparticular, 630A through 640A of FIG. 6A substantially correspond to535B through 545B, respectively, of FIG. 5C.

FIG. 6B illustrates another example of floor revocation in accordancewith an embodiment of the invention. In particular, while FIG. 6Aillustrates an example of floor-revocation for AT C initiated by AT Citself, FIG. 6B illustrates an example whereby AT C's floor revocationis initiated by another AT (i.e., AT A). Similar to FIG. 6A, FIG. 6Billustrates an example whereby ATs A . . . X are already engaged in agroup communication session with ATs A, B and C each holding anon-exclusive floor and speaking to the group. Thus, FIG. 6B can beconsidered to be a continuation of the process of FIG. 5C, because FIG.5C establishes a group communication session with similar conditions.

Referring to FIG. 6B, assume that AT A is a high-priority user orsuperuser, 600B. In the embodiment of FIG. 6B, being a ‘superuser’ orhigh-priority user means that AT A has revocation privileges for one ormore other group session participants. In an example, the priorities ofATs for revocation privileges can be similar to the manner in which theapplication server 170 is configured to evaluate contendingfloor-requests as noted above. For example, the ‘superuser’ authoritiescan be established as follows, whereby each AT can revoke non-exclusivefloors for any AT having a lower priority:

TABLE 7 Priority Tables to Evaluate Floor Revocation Requests DirectCalls Adhoc Closed Closed Chat Pri- Calls Group Calls room Calls Userority User Priority User Priority User Priority A 9 A 9 A 9 A 9 B 7 B 7B 5 B 5 C 7 C 7 C 7 C 7 D 7 D 7 D 1 D 1 E . . . X 7 E . . . X 7 E . . .X 3 E . . . X 3

As shown in Table 7, AT A is the highest-priority user for each type ofcall (i.e., priority level=9) and thereby has permission to revoke thefloor for any AT. AT B can revoke the floor for ATs D . . . X if thegroup communication session is a closed group call or a closed chat roomcall, and so on. As will be appreciated, this simply represents onemanner in which a given group session participant can achieve revocationprivileges or revocation authority with respect to one or more otherparticipants of the group communication session.

Turning back to FIG. 6B, after 550C of FIG. 5C, at some point during thegroup communication session while ATs A, B and C are each sending mediato the group, assume that AT A determines that its user desires torevoke AT C's floor, 605B. As will be appreciated, the user of AT A candetermine to revoke AT C's floor for any of a number of reasons. Forexample, the user of AT C may be very loud and distracting to the userof AT A, the user of AT A may have something important to say and doesnot want to be interrupted by the user of AT C, and so on. While AT A inthe embodiment of FIG. 6B is a current holder of a non-exclusive floorto the group communication session, it will be appreciated that otherembodiments can be directed to scenarios where a non-floorholder or‘listener’ to the session is a superuser. In this case, it will beappreciated that the user that invokes his/her revocation authority overanother user, such that the other user is forced to give up his/hernon-exclusive floor, need not him/herself currently have a non-exclusivefloor to the session. The determination of 605B can be based on input bythe user of AT A into AT A.

Responsive to the determination of 605B, AT A transmits a request torevoke the non-exclusive floor of AT C to the RAN 120, which forwardsthe request to the application server 170, 610B. The application server170 receives the request to revoke the non-exclusive floor from AT C,and determines whether AT A has sufficient privileges to revoke thefloor of AT C, 615B. In this example, it is assumed that AT A hassufficient revocation privileges to revoke the floor of AT C. As such,the application server 170 drops AT C's non-exclusive floor and thennotifies that AT C that its floor has been revoked, 620B. AT Cacknowledges the floor-revocation message in 625B. While not shown inFIG. 6B, AT C can also optionally notify its user with regard to thefloor-revocation (e.g., so that the user of AT C is aware that his/herspeech is no longer being sent to the group).

At this point, the application server 170 stops mixing media from inputstream C into any of the output streams to ATs A . . . X, 630B. Afterrevoking AT C's non-exclusive floor to the group communication session,it will be appreciated that ATs A and B still hold non-exclusive floorsto the hybrid group communication session and continue to send media tothe application server 170, as input streams A and B, respectively, fortransmission to the group, 635B and 640B. Next, 645B through 655Bsubstantially correspond to 630A through 640A of FIG. 6A, respectively,and as such will not be described further for the sake of brevity

FIG. 6C illustrates another example of floor revocation in accordancewith an embodiment of the invention. In particular, while FIG. 6Aillustrates an example of floor-revocation for AT C initiated by AT Citself and FIG. 6B illustrates an example of floor-revocation initiatedby another AT, FIG. 6C illustrates an example whereby the decision torevoke AT C's floor originates at the application server 170. Similar toFIGS. 6A and 6B, FIG. 6C illustrates an example whereby ATs A . . . Xare already engaged in a group communication session with ATs A, B and Ceach holding a non-exclusive floor and speaking to the group. Thus, FIG.6C can be considered to be a continuation of the process of FIG. 5C,because FIG. 5C establishes a group communication session with similarconditions.

Referring to FIG. 6C, after 550C of FIG. 5C, at some point during thegroup communication session while ATs A, B and C are each sending mediato the group, assume that the application server 170 determines torevoke AT C's floor, 600C. As will be appreciated, the applicationserver 170 can determine to revoke AT C's floor for any of a number ofreasons. For example, assume that the threshold or maximum number ofnon-exclusive floor-holders is three, such that ATs A, B and C aremonopolizing the floor-access. Next, a floor-request arrives from a userwith a higher-priority than AT C. In this case, the application server170 can revoke AT C's floor so that the floor can be allocated to thehigher-priority user. In another example, the application server 170 cantrack how long the floor has been allocated to AT C and can revoke ATC's floor when the timer expires. It will be appreciated that there aremany other reasons that can cause the application server 170 to reachthe decision to revoke AT C's floor in 600C. Also, the time limit forfloor-allocation can be omitted entirely in certain embodiments, such aswhen the group communication session corresponds to a lecture where thelecturer would be expected to hold the floor for most if not all of thesession. In another example, the application server 170 can detectundesirable audio patterns (e.g., such as white-noise, loud honkinghorns in a traffic jam, emergency sirens, intentional jamming sound froma malicious user, etc., which is not good for mixed audio), and revokethe floor of ATs originating such audio.

In a further alternative example, instead of simply deciding to revokethe floor of one or more ATs at the application server 170 and thenissuing the revocation-order, the application server 170 can query orprompt a superuser of the group communication session before taking suchaction. This alternative example merges FIG. 6C with FIG. 6B in a sense,such that the application server 170 provides recommendations to asuperuser for floor-revocation, but the final authority still resideswith the superuser (e.g., AT A, in FIG. 6B).

After determining to revoke AT C's non-exclusive floor in 600C, theapplication server 170 drops AT C's non-exclusive floor and thennotifies that AT C that its floor has been revoked, 605C. AT Cacknowledges the floor-revocation message in 610C. While not shown inFIG. 6C, AT C can also optionally notify its user with regard to thefloor-revocation (e.g., so that the user of AT C is aware that his/herspeech is no longer being sent to the group).

At this point, the application server 170 stops mixing media from inputstream C into any of the output streams to ATs A . . . X, 615C. Afterrevoking AT C's non-exclusive floor to the group communication session,it will be appreciated that ATs A and B still hold non-exclusive floorsto the hybrid group communication session and continue to send media tothe application server 170, as input streams A and B, respectively, fortransmission to the group, 620C and 625C. Next, 630C through 640Csubstantially correspond to 630A through 640A of FIG. 6A, respectivelyand/or 645B through 655B of FIG. 6B, respectively, and as such will notbe described further for the sake of brevity

The group communication session described above with respect to FIGS. 5Athrough 6C may correspond to a group communication session supported byIP multicasting protocols, or IP unicasting protocols. In IPmulticasting, a downlink broadcast channel (BCH) carries a singlemulticast flow within one or more sectors to reach each ‘listening’multicast group member, while a separate scheduling message (e.g., abroadcast overhead message (BOM)) is transmitted on a downlink controlchannel that indicates how the multicast group members can tune to thedownlink BCH. In IP unicasting, each group message is transmitted toeach group communication session participant, or multicast group member,as a separate unicast message addressed to each group memberindividually.

In the embodiments described above, in accordance with the defaultmixing rule, media frames from one or more non-exclusive floor-holdersare either forwarded to the rest of the communication group withoutmixing (e.g., 565A of FIG. 5A, 535B with respect to the output framesfor delivery to ATs A and B, etc.) or by first mixing some of the mediaframes together for delivery as mixed frame(s) to at least one target inthe communication group (e.g., 535B of FIG. 5B with respect to theoutput frames for delivery to ATs C . . . X, 540C of FIG. 5C, etc.). Ineither case, the application server 170 executes the same default mixingrule for its decision of how to generate each particular output frame inthe respective output streams being delivered to the various groupmembers in the communication group. Embodiments of the invention to bedescribed in more detail below permit user-specified mixing preferences,which can potentially override the default mixing rule, to be evaluatedand enforced by the application server 170 for the selectiveframe-mixing.

FIG. 7 illustrates a server-based process of selectively mixing mediaframes into output frames in accordance with another embodiment of theinvention. The process of FIG. 7 is executed at the application server170.

Referring to FIG. 7, the application server 170 obtains a user-specifiedmixing preference for at least one access terminal in the communicationgroup that is different than a default mixing rule for a groupcommunication session. The user-specified mixing preference can beobtained either before the group communication session starts as apre-configured parameter, or alternatively within a message that isreceived during an active group communication session. If theuser-specified mixing preference is obtained during the active groupcommunication session, the user-specified mixing preference can causethe application server 170 to modify how it is selectively mixing mediaframes into output frames for delivery to the at least one accessterminal. For example, if AT C is a non-exclusive floorholder ATproviding media frames for the group communication session and AT Dprovides, while in-session, the user-specified mixing preferencerequesting that AT C's media be blocked from delivery to AT D, then theapplication server 170 stops adding AT C's media to output frames beingdelivered to AT D.

The user-specified mixing preference can be obtained either from the atleast one access terminal itself or alternatively from a separateadministrator. For example, an operator of AT A may determine that itdoes not want to present media from AT D, and may thereby configure theuser-specified mixing preference to block (or de-emphasize) AT D's mediafrom delivery to AT A. For example, AT D's media can be omittedaltogether, or simply de-emphasized (e.g., reduced in volume relative tomedia from other ATs, etc.) In an alternative scenario, an InformationTechnology (IT) administrator for the group communication session candesignate certain ATs as priority ATs (e.g., project leaders, CEOs,etc.) such that, whenever media is received from any priority AT, mediafrom any non-priority ATs are excluded (or de-emphasized) from outputframes delivered to the communication group. In the IT administratorexample, the same user-specified mixing preference can be attached tomultiple (or even all) ATs participating in the group communicationsession.

The user-specified mixing preference can thereby employ a rankingmechanism to prioritize a first subset of high-ranked group members inthe communication group relative to group members that do not belong tothe first subset, to de-prioritize a second subset of low-ranked groupmembers in the communication group relative to group members that do notbelong to the second subset, or both. So, in accordance with theuser-specified mixing preference, media from the first subset of groupmembers can function to include (or emphasize, such as by increasingrelative volume) media from group members in the first subset and/or toexclude (or de-emphasize) media from other group members that are not inthe first subset, while media from the second subset of group members issimply excluded altogether (or merely de-emphasized) irrespective ofwhether media from any group members in the first subset is present.

As will be appreciated, not all ATs or group members participating inthe group communication session are necessarily associated with anyuser-specified mixing preference. Any ATs or group members that do nothave an associated user-specified mixing preference will have theiroutput frames generated in accordance with the default mixing rule notedabove. Also, different ATs or group members participating in the groupcommunication session can be associated with different user-specifiedmixing rules. Further, the ATs associated with user-specified mixingpreferences can correspond either to non-exclusive floorholder ATs or tonon-floorholder ATs.

Further, the user-specified mixing preference can be either a staticparameter that remains unchanged, or a dynamic parameter that can changebased on circumstance. For example, if AT B is operated by a co-workerof AT A, an example user-specified mixing preference for AT B candesignate AT A as belonging to the first subset (e.g., highlyprioritized or ranked) during work-hours and can designate AT A asbelonging to the second subset (e.g., low priority or ranking) duringnon-work hours. In another example, if a particular speaker ismonopolizing a conversation by talking constantly during a call, thatparticular speaker can transition to either a higher or lower ranking.So, the particular speaker can start the call with a low priority andend up with a high priority, or vice versa. Thereby, one or more currentparameters (e.g., a current time, a current call context, etc.) can beused to dynamically change at least some portion of the user-specifiedmixing preference in at least one implementation.

Returning to FIG. 7, at some point after the group communication sessionis established, the application server 170 grants a non-exclusive floorfor the group communication session to each of a plurality of accessterminals from the communication group, 705. The setup and floor-grantprocedure at 705 can be implemented as discussed above with respect toany of FIGS. 5A-6C in an example. Also, as noted above, theuser-specified mixing preference for the at least one access terminalcan be obtained at 700 prior to session setup, or the user-specifiedmixing preference can alternatively be obtained during the groupcommunication session. Thereby, even though 700 is shown in FIG. 7 asbeing before 705, 700 can actually occur after 705 in terms of executionorder in certain scenarios. However, it is assumed that 700 occurs atsome point prior to 710, which is described next.

At 710, the application server 170 receives a media frame from each ofthe plurality of access terminals for transmission in a given timeslotto the communication group in accordance with the non-exclusive floorgrants. At this point, instead of executing the default mixing rule foreach AT in the communication group, the application server 170 generatesone or more output frames by selectively mixing the media framesreceived from the plurality of access terminals, wherein the one or moreoutput frames include at least one output frame to be delivered to theat least one access terminal that is selectively mixed in accordancewith the user-specified mixing preference. Thereby, even if some outputframes are still generated based on the default mixing rule, the outputframe(s) targeted to the at least one access terminal for which theuser-specified mixing preference is established at 700 are generated inaccordance with the user-specified mixing preference at 715. Aftergenerating the one or more output frames at 715, the application server170 transmits the one or more output frames for the given timeslot tothe communication group, 720.

As discussed above with respect to FIG. 7, the user-specified mixingpreference obtained at 700 can be obtained either before initiation ofthe group communication session (e.g., FIG. 8B), or alternatively can bereceived while the group communication session is active (e.g., FIG.8A).

Referring to FIG. 8A, while the group communication session is active,800A, AT A or an administrator of AT A sends a message that indicates anew or updated user-specified mixing preference for AT A, 805A. Theapplication server 170 receives the user-specified mixing preference forAT A and modifies how media frames are being mixed for AT A during thegroup session based on the user-specified mixing preference for AT A,810A. For example, at 810A, if the application server 170 was preparingoutput frames for delivery to AT A based on the default mixing ruleprior to 805A, the application server 170 will stop using the defaultmixing rule and will switch to the user-specified mixing preference forAT A that was received at 805A. In an alternative example, at 810A, ifthe application server 170 was preparing output frames for delivery toAT A based on an older version of the user-specified mixing preferenceprior to 805A, the application server 170 will stop using the olderversion of the user-specified mixing preference and will switch to theupdated user-specified mixing preference for AT A that was received at805A.

Referring to FIG. 8B, before the group communication session is active,800B, AT A or an administrator of AT A configures a new or updateduser-specified mixing preference for AT A, 805B. The application server170 receives and stores the user-specified mixing preference for AT A,810B. In an example, the user-specified mixing preference received bythe application server 170 can function to replace an older version ofthe user-specified mixing preference maintained by the applicationserver 170 prior to 805B, if present. At some later point in time, thegroup communication session is initiated, 815B, and the applicationserver 170 will selectively mix media into output frames for delivery toAT A in accordance with the user-specified mixing preference for AT Athat was received at 805B and stored at 810B, 820B.

FIG. 9 illustrates a group communication session that incorporates someof the aspects described above with respect to FIGS. 7-8B in accordancewith an embodiment of the invention.

Referring to FIG. 9, before a group communication session between aparticular communication group is initiated, an administrator configuresa user-specified mixing preference for AT A that instructs theapplication server 170 to de-emphasize media AT D or AT E with respectto AT A (e.g., to reduce an association volume of media from AT D and ATE or to exclude media from AT D and AT E altogether from delivery to ATA, etc.), 900. In an example, the user-specified mixing preference canbe implemented because AT A does not have sufficient security clearanceto monitor media from AT D or AT E, or because AT D and AT E areoperated by low-priority users, etc. In an example, the user-specifiedmixing preference for AT A can cause the application server 170 to block(or de-emphasize) all media from ATs D and E from delivery to AT A, oralternatively can function to exclude (or de-emphasize) media from ATs Dor E from delivery to AT A only when media frames from other ATs areavailable for mixing in a particular timeslot.

Also, still before the group communication session is initiated, AT Bconfigures a user-specified mixing preference for AT B that indicates aparticular interest in media from AT D, 905. In an example, theuser-specified mixing preference can be implemented because an operatorof AT B identifies an operator of AT D to be particularly important tothe conservation. The user-specified mixing preference for AT B willcause the application server 170 to exclude (or de-emphasize) media fromany other AT (if any) whenever media from AT D is available for mixing.

At 910, the application server 170 sets up the group communicationsession that includes ATs A . . . G as active participants, and issuesnon-exclusive floor grants to each of ATs C . . . G. The actual inputstreams (which are comprised of a series of input media frames) from ATsC . . . G are not shown explicitly in FIG. 9 but are assumed to bepresent. The setup procedure of 910 is not shown in detail in FIG. 9 forthe sake of simplicity, but the setup procedure can be implemented usingsetup procedures as shown above in any of FIGS. 5A-6C.

At 915, the application server 170 selectively mixes frames based on theuser-specified mixing preferences and/or the default mixing rule foreach of ATs A . . . G. In particular, output frames for AT A are mixedbased on the user-specified mixing preference from 900, which results inoutput frames conforming to Stream C+F+G (i.e., a series of outputframes that each include and/or emphasize media mixed from media framesthat originate from each of ATs C, F and G for a particular timeslot,with media frames from ATs D and E being excluded or de-emphasized). Theoutput frames for AT B are selectively mixed (in this case, unmixed)based on the user-specified mixing preference from 905, which resultsoutput frames conforming to Stream D (i.e., a stream of unmixed outputframes mapping to media frames from AT D). The output frames for ATs C .. . G are mixed based on the default mixing rule as noted above. As willbe appreciated, this results in output frames for AT C conforming toStream D+E+F+G, output frames for AT D conforming to Stream C+E+F+G,output frames for AT E conforming to Stream C+D+F+G, output frames forAT F conforming to Stream C+D+E+G, and output frames for AT G conformingto Stream C+D+E+F. The respective output frames (or output streams)generated at 915 are forwarded to ATs A . . . G, 920.

During the group communication session, AT C sends a message to theapplication server 170 that requests the application server 170 toimplement a user-specified mixing preference for AT C which specifies aparticular interest in media from AT B and a disinterest in media fromATs F and G, 925. Also, AT B sends a message to the application server170 that requests the application server 170 to implement an updateduser-specified mixing preference for AT B which specifies a particularinterest in media from AT E in addition to AT D, 930.

At 935, the application server 170 selectively mixes frames based on theuser-specified mixing preferences and/or the default mixing rule foreach of ATs A . . . G. In particular, output frames for AT A are mixedbased on the user-specified mixing preference from 900, which results inoutput frames conforming to Stream C+F+G (i.e., a series of outputframes overtime that each include media mixed from media frames fromeach of ATs C, F and G, with media frames from ATs D and E beingexcluded or de-emphasized). The output frames for AT B are mixed basedon the updated user-specified mixing preference from 930, which resultsoutput frames conforming to Stream D+E. The output frames for AT C aremixed based on the user-specified mixing preference from 925, whichresults output frames conforming to Stream D+E (i.e., no media availablefrom AT B because AT B is not a floorholder, media from AT F and AT G isexcluded or de-emphasized as requested, and media from AT C is alsoexcluded because the target is AT C, which leaves media from AT D and ATE to be mixed into the output frames for delivery to AT C). The outputframes for ATs D . . . G are mixed based on the default mixing rule asnoted above. As will be appreciated, this results in output frames forAT D conforming to Stream C+E+F+G, output frames for AT E conforming toStream C+D+F+G, output frames for AT F conforming to Stream C+D+E+G, andoutput frames for AT G conforming to Stream C+D+E+F. The respectiveoutput frames (or output streams) generated at 935 are forwarded to ATsA . . . G, 940.

While some of the user-defined mixing preferences discussed above relateto specifying which media sources are to be included or excluded from aparticular output frame, other user-defined mixing preferences canprioritize and/or de-prioritize media sources without excluding mediafrom de-prioritized or non-prioritized sources altogether. For example,a user-defined mixing preference specifying an interest in AT A's mediaand a disinterest in AT B's media could function to include AT A's mediaat higher-volume (e.g., emphasized) in a corresponding output frameand/or mixing AT B's media at a lower-volume (e.g., de-emphasized) inthe corresponding output frame, with any “neutral” media sources havingtheir media added to the corresponding output frame at a “normal”volume. In an alternative example, a user-defined mixing preferencespecifying an interest in AT A's media could function to include AT A'smedia in a corresponding output frame as noted above, while separatelytriggering delivery a text-transcript of AT A's media so that the targetuser can both hear or view AT A's media while also being able to read ATA's media. Thereby, the prioritized treatment of media sources inaccordance with the user-defined mixing preferences can theoreticallyextend beyond how the media source's media is treated in terms of mixingwithin the output frames, and could trigger supplemental actions (e.g.,such a text-transcript delivery).

While FIGS. 7-9 relate to selectively mixing media frames usinguser-specified mixing preferences at the application server 170, it isalso possible that the application server 170 can forward output framesincluding unmixed media to some or all of the session participants,which then perform the selective mixing operation using their respectiveuser-specified mixing preferences (or theoretically even the defaultmixing rule) locally. For example, certain ATs in the groupcommunication session can notify the application server 170 with regardto their preference to receive output frames with unmixed media tofacilitate the AT-based selective mixing operation. In another example,the application server 170 can simply forward all output frames to thesession participants as unmixed output frames.

FIG. 10 illustrates a client-based process of selectively mixing mediaframes into output frames in accordance with another embodiment of theinvention. The process of FIG. 10 is executed at a given AT that isconfigured to participate in any of the group communication sessionsdescribed above.

Referring to FIG. 10, at 1000, the given AT obtains a user-specifiedmixing preference to be enforced at the given AT. The user-specifiedmixing preference can be configured locally at the given AT, oralternatively can be configured remotely by an administrator of thegiven AT and then downloaded to the given AT. Similar to 700 of FIG. 7,the operation of 1000 can occur either before or after the groupcommunication session is initiated. The user-specified mixing preferenceobtained at 1000 for client-based execution can be configured similarlyto any of the aforementioned examples of user-specified mixingpreferences for server-based execution (e.g., dynamic context-baseduser-specified mixing preferences, etc.), and thereby will not bediscussed further for the sake of brevity.

Referring to FIG. 10, at some point after initiating of the groupcommunication session, the given AT receives an unmixed output frame forthe group communication session, 1005. For example, the output framereceived at 1005 can include unmixed media frames from each of aplurality of access terminals in the communication group that hold anon-exclusive floor for the group communication session. The given ATselectively mixes the unmixed media frames in accordance with theuser-specified mixing preference to produce a selectively mixed outputframe, 1010, and then outputs the selectively mixed output frame, 1015.Generally, 1010 is similar to 715 of FIG. 7 except for being performedfor a single AT at the AT itself instead of at the application server170.

FIG. 11 illustrates a group communication session that incorporates someof the aspects described above with respect to FIG. 10 in accordancewith an embodiment of the invention.

Referring to FIG. 11, before a group communication session between aparticular communication group is initiated, an administrator configuresa user-specified mixing preference for AT A that instructs the AT A tode-emphasize media from AT D and AT E (e.g., to reduce an associationvolume of media from AT D and AT E or to exclude media from AT D and ATE altogether from output altogether), 1100. In an example, theuser-specified mixing preference can be implemented because AT A doesnot have sufficient security clearance to monitor media from AT D or ATE, or because AT D and AT E are operated by low-priority users, etc.

Also, still before the group communication session is initiated, AT Bconfigures a user-specified mixing preference for AT B that indicates aparticular interest in media from AT D, 1105. In an example, theuser-specified mixing preference can be implemented because an operatorof AT B identifies an operator of AT D to be particularly important tothe conservation. The user-specified mixing preference for AT B maycause AT B to emphasize AT D's media whenever it is available formixing, and/or to exclude (or de-emphasize) media from any other AT (ifany) whenever media from AT D is available for mixing.

At 1110, the application server 170 sets up the group communicationsession that includes ATs A . . . G as active participants, and issuesnon-exclusive floor grants to each of ATs C . . . G (e.g., similar to910 of FIG. 9). The actual input streams (which are comprised of aseries of input media frames) from ATs C . . . G are not shownexplicitly in FIG. 11 but are assumed to be present. The setup procedureof 1110 is not shown in detail in FIG. 11 for the sake of simplicity,but the setup procedure can be implemented using setup procedures asshown above in any of FIGS. 5A-6C.

At 1115, irrespective of whether the application server 170 selectivelymixes frames based on the user-specified mixing preferences and/or thedefault mixing rule for ATs C . . . G, the application server 170forwards unmixed output frames (or unmixed media streams with outputframes that do not include mixed media) to ATs A and B. By providing theunmixed media frames from ATs C . . . G to ATs A and B, ATs A and B havethe option to mix the media themselves. Also, while not discussed inFIG. 11 in much detail, some type of output frames (mixed or unmixed)are also delivered to ATs C . . . G at 1115.

At 1120, AT A mixes the media frames from ATs A . . . G in accordancebased on the user-specified mixing preference from 1100, which resultsin output frames conforming to Stream C+F+G (i.e., a series of outputframes that each include and/or emphasize media mixed from media framesthat originate from each of ATs C, F and G for a particular timeslot,with media frames from ATs D and E being excluded or de-emphasized). At1125, AT B mixes the media frames from ATs A . . . G based on theuser-specified mixing preference from 1105, which results in outputframes conforming to Stream D (i.e., a series of output frames that eachinclude and/or emphasize media mixed from media frames that originatefrom AT D for a particular timeslot, with media frames from other ATsbeing excluded or de-emphasized). The respective output frames mixed at1120 and 1125 are then output at 1130 and 1135, respectively.

During the group communication session, assume that AT B determines toenforce an updated user-specified mixing preference for AT B whichspecifies a particular interest in media from AT E in addition to AT D,1140. Unlike FIG. 9, the server does not need to be notified of thischange because AT B is performing its selective mixing as a localoperation.

At 1145, irrespective of whether the application server 170 selectivelymixes frames based on the user-specified mixing preferences and/or thedefault mixing rule for ATs C . . . G, the application server 170continues to forward unmixed output frames (or unmixed media streamswith output frames that do not include mixed media) to ATs A and B(e.g., similar to 1115). Also, while not discussed in FIG. 11 in muchdetail, some type of output frames (mixed or unmixed) are also deliveredto ATs C . . . G at 1145.

At 1150, AT A continues to mix the media frames from ATs A . . . G inaccordance based on the user-specified mixing preference from 1100,which results in output frames conforming to Stream C+F+G (i.e., aseries of output frames that each include and/or emphasize media mixedfrom media frames that originate from each of ATs C, F and G for aparticular timeslot, with media frames from ATs D and E being excludedor de-emphasized). At 1155, AT B mixes the media frames from ATs A . . .G based on the updated user-specified mixing preference from 1140, whichresults in output frames conforming to Stream D+E (i.e., a series ofoutput frames that each include and/or emphasize media mixed from mediaframes that originate from each of ATs D and E for a particulartimeslot, with media frames from other ATs being excluded orde-emphasized). The respective output frames mixed at 1150 and 1155 arethen output at 1160 and 1165, respectively.

While some the user-defined mixing preferences discussed above relate tospecifying which media sources are to be included or excluded from aparticular output frame, other user-defined mixing preferences canprioritize and/or de-prioritize media sources without excluding mediafrom de-prioritized or non-prioritized sources altogether. For example,a user-defined mixing preference specifying an interest in AT A's mediaand a disinterest in AT B's media could function to include AT A's mediaat higher-volume (e.g., emphasized) in a corresponding output frameand/or mixing AT B's media at a lower-volume (e.g., de-emphasized) inthe corresponding output frame, with any “neutral” media sources havingtheir media added to the corresponding output frame at a “normal”volume. In an alternative example, a user-defined mixing preferencespecifying an interest in AT A's media could function to include AT A'smedia in a corresponding output frame as noted above, while separatelytriggering delivery a text-transcript of AT A's media so that the targetuser can both hear or view AT A's media while also being able to read ATA's media. Thereby, the prioritized treatment of media sources inaccordance with the user-defined mixing preferences can theoreticallyextend beyond how the media source's media is treated in terms of mixingwithin the output frames, and could trigger supplemental actions (e.g.,such a text-transcript delivery).

FIG. 12 illustrates a communication device 1200 that includes logicconfigured to perform functionality. The communication device 1200 cancorrespond to any of the above-noted communication devices, includingbut not limited to ATs application server 170, MCC module 172 and/or AT200. Thus, communication device 1200 can correspond to any electronicdevice that is configured to communicate with (or facilitatecommunication with) one or more other entities over the wirelesscommunications system 100 of FIG. 1.

Referring to FIG. 12, the communication device 1200 includes logicconfigured to receive and/or transmit information 1205. In an example,if the communication device 1200 corresponds to a wirelesscommunications device (e.g., AT 200, etc.), the logic configured toreceive and/or transmit information 1205 can include a wirelesscommunications interface (e.g., Bluetooth, WiFi, 2G, CDMA, W-CDMA, 3G,4G, LTE, etc.) such as a wireless transceiver and associated hardware(e.g., an RF antenna, a MODEM, a modulator and/or demodulator, etc.). Inanother example, the logic configured to receive and/or transmitinformation 1205 can correspond to a wired communications interface(e.g., a serial connection, a USB or Firewire connection, an Ethernetconnection through which the Internet 175 can be accessed, etc.). Thus,if the communication device 1200 corresponds to some type ofnetwork-based server (e.g., the application 170, MCC 172, etc.), thelogic configured to receive and/or transmit information 1205 cancorrespond to an Ethernet card, in an example, that connects thenetwork-based server to other communication entities via an Ethernetprotocol. In a further example, the logic configured to receive and/ortransmit information 1205 can include sensory or measurement hardware bywhich the communication device 1200 can monitor its local environment(e.g., an accelerometer, a temperature sensor, a light sensor, anantenna for monitoring local RF signals, etc.). The logic configured toreceive and/or transmit information 1205 can also include software that,when executed, permits the associated hardware of the logic configuredto receive and/or transmit information 1205 to perform its receptionand/or transmission function(s). However, the logic configured toreceive and/or transmit information 1205 does not correspond to softwarealone, and the logic configured to receive and/or transmit information1205 relies at least in part upon hardware to achieve its functionality.

Referring to FIG. 12, the communication device 1200 further includeslogic configured to process information 1210. In an example, the logicconfigured to process information 1210 can include at least a processor.Example implementations of the type of processing that can be performedby the logic configured to process information 1210 includes but is notlimited to performing determinations, establishing connections, makingselections between different information options, performing evaluationsrelated to data, interacting with sensors coupled to the communicationdevice 1200 to perform measurement operations, converting informationfrom one format to another (e.g., between different protocols such as.wmv to .avi, etc.), and so on. For example, the processor included inthe logic configured to process information 1210 can correspond to ageneral purpose processor, a digital signal processor (DSP), an ASIC, afield programmable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration. The logic configured to process information 1210 can alsoinclude software that, when executed, permits the associated hardware ofthe logic configured to process information 1210 to perform itsprocessing function(s). However, the logic configured to processinformation 1210 does not correspond to software alone, and the logicconfigured to process information 1210 relies at least in part uponhardware to achieve its functionality.

Referring to FIG. 12, the communication device 1200 further includeslogic configured to store information 1215. In an example, the logicconfigured to store information 1215 can include at least anon-transitory memory and associated hardware (e.g., a memorycontroller, etc.). For example, the non-transitory memory included inthe logic configured to store information 1215 can correspond to RAMmemory, flash memory, ROM memory, EPROM memory, EEPROM memory,registers, hard disk, a removable disk, a CD-ROM, or any other form ofstorage medium known in the art. The logic configured to storeinformation 1215 can also include software that, when executed, permitsthe associated hardware of the logic configured to store information1215 to perform its storage function(s). However, the logic configuredto store information 1215 does not correspond to software alone, and thelogic configured to store information 1215 relies at least in part uponhardware to achieve its functionality.

Referring to FIG. 12, the communication device 1200 further optionallyincludes logic configured to present information 1220. In an example,the logic configured to present information 1220 can include at least anoutput device and associated hardware. For example, the output devicecan include a video output device (e.g., a display screen, a port thatcan carry video information such as USB, HDMI, etc.), an audio outputdevice (e.g., speakers, a port that can carry audio information such asa microphone jack, USB, HDMI, etc.), a vibration device and/or any otherdevice by which information can be formatted for output or actuallyoutputted by a user or operator of the communication device 1200. Forexample, if the communication device 1200 corresponds to AT 200 as shownin FIG. 3, the logic configured to present information 1220 can includethe display 224. In a further example, the logic configured to presentinformation 1220 can be omitted for certain communication devices, suchas network communication devices that do not have a local user (e.g.,network switches or routers, remote servers, etc.). The logic configuredto present information 1220 can also include software that, whenexecuted, permits the associated hardware of the logic configured topresent information 1220 to perform its presentation function(s).However, the logic configured to present information 1220 does notcorrespond to software alone, and the logic configured to presentinformation 1220 relies at least in part upon hardware to achieve itsfunctionality.

Referring to FIG. 12, the communication device 1200 further optionallyincludes logic configured to receive local user input 1225. In anexample, the logic configured to receive local user input 1225 caninclude at least a user input device and associated hardware. Forexample, the user input device can include buttons, a touchscreendisplay, a keyboard, a camera, an audio input device (e.g., a microphoneor a port that can carry audio information such as a microphone jack,etc.), and/or any other device by which information can be received froma user or operator of the communication device 1200. For example, if thecommunication device 1200 corresponds to AT 200 as shown in FIG. 3, thelogic configured to receive local user input 1225 can include the keypad226, button 228, etc. In a further example, the logic configured toreceive local user input 1225 can be omitted for certain communicationdevices, such as network communication devices that do not have a localuser (e.g., network switches or routers, remote servers, etc.). Thelogic configured to receive local user input 1225 can also includesoftware that, when executed, permits the associated hardware of thelogic configured to receive local user input 1225 to perform its inputreception function(s). However, the logic configured to receive localuser input 1225 does not correspond to software alone, and the logicconfigured to receive local user input 1225 relies at least in part uponhardware to achieve its functionality.

Referring to FIG. 12, while the configured logics of 1205 through 1225are shown as separate or distinct blocks in FIG. 12, it will beappreciated that the hardware and/or software by which the respectiveconfigured logic performs its functionality can overlap in part. Forexample, any software used to facilitate the functionality of theconfigured logics of 1205 through 1225 can be stored in thenon-transitory memory associated with the logic configured to storeinformation 1215, such that the configured logics of 1205 through 1225each performs their functionality (i.e., in this case, softwareexecution) based in part upon the operation of software stored by thelogic configured to store information 1215. Likewise, hardware that isdirectly associated with one of the configured logics can be borrowed orused by other configured logics from time to time. For example, theprocessor of the logic configured to process information 1212 can formatdata into an appropriate format before being transmitted by the logicconfigured to receive and/or transmit information 1205, such that thelogic configured to receive and/or transmit information 1205 performsits functionality (i.e., in this case, transmission of data) based inpart upon the operation of hardware (i.e., the processor) associatedwith the logic configured to process information 1210.

Generally, unless stated otherwise explicitly, the phrase “logicconfigured to” as used throughout this disclosure is intended to invokean embodiment that is at least partially implemented with hardware, andis not intended to map to software-only implementations that areindependent of hardware. Also, it will be appreciated that theconfigured logic or “logic configured to” in the various blocks are notlimited to specific logic gates or elements, but generally refer to theability to perform the functionality described herein (either viahardware or a combination of hardware and software). Thus, theconfigured logics or “logic configured to” as illustrated in the variousblocks are not necessarily implemented as logic gates or logic elementsdespite sharing the word “logic.” Other interactions or cooperationbetween the logic in the various blocks will become clear to one ofordinary skill in the art from a review of the embodiments describedbelow in more detail.

The various embodiments may be implemented on any of a variety ofcommercially available server devices, such as server 1300 illustratedin FIG. 13. In an example, the server 1300 may correspond to one exampleconfiguration of the application server 170 or MCC 172 described above.In FIG. 13, the server 1300 includes a processor 1301 coupled tovolatile memory 1302 and a large capacity nonvolatile memory, such as adisk drive 1303. The server 1300 may also include a floppy disc drive,compact disc (CD) or DVD disc drive 1306 coupled to the processor 1301.The server 1300 may also include network access ports 1304 coupled tothe processor 1301 for establishing data connections with a network1307, such as a local area network coupled to other broadcast systemcomputers and servers or to the Internet. In context with FIG. 12, itwill be appreciated that the server 1300 of FIG. 13 illustrates oneexample implementation of the communication device 1200, whereby thelogic configured to transmit and/or receive information 1205 correspondsto the network access ports 1304 used by the server 1300 to communicatewith the network 1307, the logic configured to process information 1210corresponds to the processor 1301, and the logic configuration to storeinformation 1215 corresponds to any combination of the volatile memory1302, the disk drive 1303 and/or the disc drive 1306. The optional logicconfigured to present information 1220 and the optional logic configuredto receive local user input 1225 are not shown explicitly in FIG. 13 andmay or may not be included therein. Thus, FIG. 13 helps to demonstratethat the communication device 1200 may be implemented as a server, inaddition to an AT implementation as in 200 of FIG. 3.

While embodiments have been above-described generally to audio-basedgroup communication sessions, other embodiments can be directed to othertypes of group communication session, such as video conferences, etc.Also, while embodiments have been directed above to RTP packets, it willbe appreciated that other embodiments of the invention can be directedto other types of media packets. For example, in a system operating inaccordance with RealNetworks protocols, a RDT packet may be used insteadof an RTP packet. In other words, as noted above, while embodiments havegenerally been directed to an implementation in accordance with EVRC-Aprotocols, other Vocoders (e.g., AMR, etc.) that have a discreteframe-rate set can be used in other embodiments of the invention.

Those of skill in the art will appreciate that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Further, those of skill in the art will appreciate that the variousillustrative logical blocks, modules, circuits, and algorithm stepsdescribed in connection with the embodiments disclosed herein may beimplemented as electronic hardware, computer software, or combinationsof both. To clearly illustrate this interchangeability of hardware andsoftware, various illustrative components, blocks, modules, circuits,and steps have been described above generally in terms of theirfunctionality. Whether such functionality is implemented as hardware orsoftware depends upon the particular application and design constraintsimposed on the overall system. Skilled artisans may implement thedescribed functionality in varying ways for each particular application,but such implementation decisions should not be interpreted as causing adeparture from the scope of the present invention.

The various illustrative logical blocks, modules, and circuits describedin connection with the embodiments disclosed herein may be implementedor performed with a general purpose processor, a digital signalprocessor (DSP), an application specific integrated circuit (ASIC), afield programmable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The methods, sequences and/or algorithms described in connection withthe embodiments disclosed herein may be embodied directly in hardware,in a software module executed by a processor, or in a combination of thetwo. A software module may reside in RAM memory, flash memory, ROMmemory, EPROM memory, EEPROM memory, registers, hard disk, a removabledisk, a CD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such that theprocessor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC. The ASIC may reside in a user terminal (e.g., access terminal). Inthe alternative, the processor and the storage medium may reside asdiscrete components in a user terminal

In one or more exemplary embodiments, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by acomputer. By way of example, and not limitation, such computer-readablemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage or other magnetic storage devices, or anyother medium that can be used to carry or store desired program code inthe form of instructions or data structures and that can be accessed bya computer. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

While the foregoing disclosure shows illustrative embodiments of theinvention, it should be noted that various changes and modificationscould be made herein without departing from the scope of the inventionas defined by the appended claims. The functions, steps and/or actionsof the method claims in accordance with the embodiments of the inventiondescribed herein need not be performed in any particular order.Furthermore, although elements of the invention may be described orclaimed in the singular, the plural is contemplated unless limitation tothe singular is explicitly stated.

What is claimed is:
 1. A method of operating a server configured toarbitrate and/or mediate a group communication session between acommunication group, comprising: obtaining a user-specified mixingpreference for at least one access terminal in the communication groupthat is different than a default mixing rule for the group communicationsession; granting a non-exclusive floor for the group communicationsession to each of a plurality of access terminals from thecommunication group; receiving a media frame from each of the pluralityof access terminals for transmission in a given timeslot to thecommunication group in accordance with the non-exclusive floor grants;generating one or more output frames by selectively mixing the mediaframes received from the plurality of access terminals, wherein the oneor more output frames include at least one output frame to be deliveredto the at least one access terminal that is selectively mixed inaccordance with the user-specified mixing preference; and transmittingthe one or more output frames for the given timeslot to thecommunication group.
 2. The method of claim 1, wherein theuser-specified mixing preference is a stored parameter that isconfigured by at least one operator of the at least one access terminalor an administrator of the at least one access terminal that ismaintained by the server prior to the group communication session beingestablished.
 3. The method of claim 1, further comprising: receiving amessage from the at least one access terminal or an administrator of theat least one access terminal that indicates the user-specified mixingpreference, wherein the generating modifies how the at least one outputframe is generated based on the user-specified mixing preferenceindicated in the message as compared to how one or more other outputframes for the at least one access terminal were generated earlier inthe group communication session.
 4. The method of claim 1, wherein theuser-specified mixing preference includes: prioritizing a first subsetof high-ranked group members in the communication group relative togroup members that do not belong to the first subset, and/orde-prioritizing a second subset of low-ranked group members in thecommunication group relative to group members that do not belong to thesecond subset.
 5. The method of claim 4, wherein a given access terminalfrom the plurality of access terminals is in the first subset, andwherein the user-specified mixing preference directs the generating togenerate the at least one output frame by including or emphasizing,within the at least one output frame, media contained in a given mediaframe from the given access terminal and excluding or de-emphasizingmedia contained in one or more other media frames from one or more otheraccess terminals that are not in the first subset.
 6. The method ofclaim 4, wherein a given access terminal from the plurality of accessterminals is in the second subset, and wherein the user-specified mixingpreference directs the generating to generate the at least one outputframe by excluding or de-emphasizing, from the at least one outputframe, media contained in a given media frame from the given accessterminal.
 7. The method of claim 1, wherein at least one other outputframe from the one or more output frames is configured to be deliveredto at least one other access terminal in the communication group that isnot associated with any user-specified mixing preference, and whereinthe at least one other output frame is mixed in accordance with thedefault mixing rule for the group communication session.
 8. The methodof claim 1, wherein the user-specified mixing preference for the atleast one access terminal is a first user-specified mixing preference,wherein a second user-specified mixing preference different from thefirst user-specified mixing preference is established for at least oneother access terminal, and wherein the one or more output frames includeat least one other output frame to be delivered to the at least oneother access terminal that is selectively mixed in accordance with thesecond user-specified mixing preference.
 9. The method of claim 1,wherein the at least one access terminal is among the plurality ofaccess terminals, or wherein the at least one access terminal is notamong the plurality of access terminals.
 10. The method of claim 1,wherein the user-specified mixing preference is dynamically determinedbased on one or more current parameters.
 11. The method of claim 10,wherein the one or more current parameters include a current time and/ora current call context.
 12. A method of operating an access terminalconfigured to participate in a group communication session between acommunication group that is arbitrated and/or mediated by a server,comprising: obtaining a user-specified mixing preference for the accessterminal; receiving an output frame for the group communication sessionthat includes unmixed media frames from each of a plurality of accessterminals in the communication group that hold a non-exclusive floor forthe group communication session; selectively mixing the unmixed mediaframes in accordance with the user-specified mixing preference toproduce a selectively mixed output frame; and outputting the selectivelymixed output frame.
 13. The method of claim 12, wherein theuser-specified mixing preference is configured by an operator of theaccess terminal or an administrator of the access terminal prior to thegroup communication session being established, or wherein the accessterminal or the administrator of the access terminal configures theuser-specified mixing preference during the group communication session.14. The method of claim 12, wherein the user-specified mixing preferenceincludes: prioritizing a first subset of high-ranked group members inthe communication group relative to group members that do not belong tothe first subset, and/or de-prioritizing a second subset of low-rankedgroup members in the communication group relative to group members thatdo not belong to the second subset.
 15. The method of 14, wherein agiven access terminal from the plurality of access terminals is in thefirst subset, and wherein, based on the user-specified mixingpreference, output frame includes and/or emphasizes given mediacontained in a given media frame from the given access terminal andexcludes or de-emphasizes other media contained in other media framesfrom one or more other access terminals that are not in the firstsubset.
 16. The method of 14, wherein a given access terminal from theplurality of access terminals is in the second subset, and wherein,based on the user-specified mixing preference, the selectively mixedoutput frame excludes or de-emphasizes given media contained in a givenmedia frame from the given access terminal.
 17. The method of claim 12,wherein the user-specified mixing preference is dynamically determinedbased on one or more current parameters.